If you’re into SEO, I’m sure you’ve read about how, from a backlink perspective, it matters if your sites are all hosted on the same IP or C class block of IP addresses.
If you’re not familiar with this concept, here is a quick explanation…
Every website is hosted at an IP address such as 123.123.123.123. Each set of numbers, separated by a period is called a class and is either A, B, C or D. Many people believe that Google and other search engines discount the value of links from one site to another if they are hosted on the same IP address or and IP address in the same C class.
This idea is based on the fact that in the past, many people were hosting dozens or hundreds of sites on the same IP address, filling it with fluff content stuffed with keywords and linking them to real sites in an attempt to improve their ranking. This worked quite well.
One day, many people using this technique found that their sites were no longer ranking well and it was assumed that Google made a change to their system to heavily discount the value of links if they were from sites on the same IP or C class block of IP addresses.
Since then, a bunch of hosts such as SEOHosting.com have sprung up that allow you to host your sites on IP addresses from different C class blocks. Most SEO experts swear that this makes a huge difference and still use the same technique I mentioned before, but using different C class IPs for each site.
I personally host dozens of sites on the same IP, all of which cross link to each other and rank extremely well for their target keywords; most are #1 or #2 in Google. I noticed they jumped to these high ranks shortly after I optimized the cross links between them.
Based on this, I’ve formed the opinion that Google doesn’t discount links from sites on the same IP as much as many believe. It could be that if all or the majority of your backlinks are from sites on the same IP, then you’ll get penalized. Only Google knows for sure, right? Maybe we can get some insight into how this works.
I’m going to run an experiment which will hopefully shed some light on how Google treats backlinks from the same IP vs. the same C class vs. different C classes.
I’m going to outline how this experiment will work very shortly after I get the groundwork laid for it so check back!
